Furnace and method of operating the same



Aug. 2,1927 1,637,473

A. L. CULBERTSON FURNACE AND METHOD OF OPERATING THE SAME Filed Jan. 20, 1926 3 Sheets-Sheet l gnbcufo:

QA M fitter/M01 0 v MW/Y Qw Aug. 2, 1927.

A. L. CULBERTSON FURNACE AND METHOD OF OPERATING THE SAME 3 SheetsSheet 2 Filed Jan. 20, 1926 avwenboz W 1". 2,220.15 A Site Ema. wa /m2? Aug. 2, 1927. v

A. L. C ULBERTSON FURNACE AND METHOD OF OPERATING THE SAME Filed Jan.20, 192s s Sheets-Sheet 3 minimum I Qfivwmtoz W 1. Cam

35% flaw M 0 7 Patented Aug. 2, 1927.

UNITED STATES PATENT OFFICE.

ALBERT L. CULBERTSON, OF MOUNT VERNON, OHIO, ASSIGNOR TO THE CHAPMAN- STEIN FURNACE (30., OF MOUNT VERNON, OHIO, A CORPORATION OF OHIO.

summon AND METHOD or ornnn'r'mo THE SAME.

Application filed January 20, 1926. Serial No. 82,423.

This "invention aims to provide a more efiicient heat interchange and more uniform heat distribution between the .hot gases passing through the heating chamber of a furnace, and material upon the furnace hearth. The invention has particular application to glass furnaces wherein molten glass is heated within a rotary hearth while being brought to and maintained at the proper temperature for subsequent glass making operations, and is illustrated as applied to a furnace of that type. In the draW1ngs- Fig.l is a vertical sectional view of a glass furnace adapted to operate in accordance with the invention, the section being taken on line 1-1 of Fig. 2.

Fig. 2 is a transverse sectional view taken on lineEZ-Q of Fig. 1, looking in the direction of the arrows.

Fig. 3 is a transverse vertical sectional view on line 3-3 of Fig. 2, looking in the direction of the arrows.

Fig. 4 is a view similar to Fig. 1 with certain parts cut away but illustrating the modified furnace construction.

F ig. 5 is a transverse sectional view showing the invention as applied to a different type of furnace. g

In accordance with the present invention, the hot gases upon entering the heating chamber, preferably after being preheated in a recuperator as hereinafter described, are passed laterally across the heating chamber at an upper level from which they heat the hearth by radiation, and are then passed backacross the chamber at a lower level directly over the material carried by the hearth, to heat the latter by direct contact. The spent gases are then drawn off from the heating chamber at this lower level, preferably to pass downwardly through a recuperator as hereinafter described. In conjunction with the double flow of the hot gases as above described, the hearth is moved to shift the material to be heated-with refer-. ence to the path of flow of the gases, thus the movement of the gases and the movement of thematerial as above described, coacts to produce maximum uniformity of heating.

Heretofore furnaces 'of the above type have usually been heated by a single inlet and, a single outlet port located at the same level, forming uneven currents of the hot gases in different parts of the chamber, and oftentimes exhausting gases before their heat was sufficiently given up. Also, due to theexcessive size of the single port it has been impossible to obtain the intimate mixture ofthe air andfuel necessary to obtain maximum flame temperatures with their consequent fuel economy. Moreover, when a serles of small ports are used, it is possible to lower the crown of the furnace to its most efiicient height for proper combustion and heat radiation. Heretofore the use of a single port for firing and a single exhaust port has necessitated the construction of a high crown which has made it impossible to obtain best efficiency. According to the present invention, it is possible to project the incoming gases in a comparatively thin and uniform sheet across the upper part of the heating chamber and then pass them back across the hearth in the reverse direction, thus bringing a. greater proportion of 7 the hot gases lntodirect contact with the material to be heated due to the thinner sheet and better spreading of the gases, and-ex haustlng them at a lowlevel to which only such gases as have given up the greater portrated in Figs. 1 and 3, a hearth 1 is provided to receive molten glass fed in in any suitable manner as by means of spout 2, the hearth being rotated by suitable mechanism, which it is not deemed necessary to describe in detail. i

A heating chamber 3 is disposed above the hearth, the inlet ports 4 being located in the upper portion of one side wall of chamber 3; preferably a sufficient number of inlet ports 4 are provided, or ports of such dimensions employed, that the hot gases passing into the chamber 3 therethrough, will form a sheet or stream which extends substantially the full width of the chamber. Oil or gas burners 5, will be employed in connection tally across the chamber 3 at an upper level just beneath the roof 6 of the chamber.

v her- 3."

This roof'I prefer to make aplane surface,

'at least in a direction transverse to the flow of the gases, and in furnaces of moderate dimensions the roof preferably is flat, as-

shown in Fig. The heat of the incommg gases during their travel across the chamber 3, as above mentioned, will be .largely given up to the roof 6 and reflected therefrom by radiation down on to the hearth. The invention enables a shallow heating chamber to be employed, thus in? creasingthe efi'ectiveness of the radiated heat, and I have found that the flat roof also increases the effectiveness and uniformity of the radiation as it prevents the focusing of the radiant heat at one spot in the center,

which is an inherent disadvantage in the sions. As above stated, however, the roof 6" is preferably plane in a direction transverse to the flow of gases through cham- After the stream of gases has :passed 1. through chamber 3 at an upper vlevel, as

I above described, the

ses are turned downwardly and pass bac lower level to the outlet ports 7 which are located'in the same side of chamber3as ports 4 and at 'a lower level. During their second travel across the chamber, the gases are directly above hearth 1 and give up their heat to the latter largely through direct con tact.

Bypassing the gases through the heating chamber 1n..the"m'anner above desciibed, a greater proportion of the gases is brought into-direct contact with the material to be heated, and the hottest gases are first allocated to the-upper part of the heatin chamher where they would naturally ten to rise inany event; and after giving up heat, thesegases are led to the bottom of the chamber where the cooler gases would naturally tend to fall, and are drawn off at that level after giving up additional heat to the material by direct contact, Thus the natural segregation of the, gases inthe chamber tends to maintain the upper'and lower oppositely moving-thinisheets of flame above menxtioned. Different areas of hearth, furthermore, will be heated by gases of more uni-' form" temperature, and: this, in conjunction with the motion of the hearth itself, will secureuniform heating of the moltenglass or other material. carried by the hearth.

Preferably the incoming air and outgoing across. hearth 1 at a ference.

gases are" passed through a recu erator denoted generally by numeral v8, suc recuperator being of the counter-current type and made up of a series. of hollow tile columns 9 (Fig. 1) the tiles of which have vertical passageways 10 to receive the incoming air to be preheated. The spaces between the hollow tile columns are partitioned off by plates 11 to form a series of horizontal passageways 12 at different levels and throu h which the spent gases pass in zigzag fas ion fromtopto bottom. The recuperator preferably is located at a lower level than chamber 3 whereby the air coming 1n through passageways 10 to inlet ports 4 will rise as it takes on heat, and the spent gases coming out through ports 7 will pass through the recuperator in a downward direction as they give up their heat.

Fig. 5 illustrates a modified form of the invention wherein the material to be heated will besupported upon a movable hearth 1 above which is located a heating chamber 3. In this embodiment of the invention, inlet ports 4 are provided in opposite side walls of the heating chamber, and outlet orts 5' are provided respectively insuch si e walls at a lower level. Two opposed streams of hot gases are thus formed by the inlet ports ,4 and such streams meet at the center of the heating chamber'as illustrated by the arrows in Fig.5, turn downwardly and pass back over the hearth 1 in opposite directions to the respective outletports 5. In this em bodiment of the invention the roof 6 of the heating chamber 3 preferably is sloped downwardly from each side toward the center of the heating chamber, thus tending to cause the opposed streams of gases toturn downwardly withless disturbance or interopposed sheets of flame, as above described, prevents overheating at the top of the furnace between the incoming sheets of hot gases, and prevents a zone of unduly low temperature at the bottom of the furnace between the lower sheets of flame. 1

While certain specific embodiments of the invention have been disclosed, it will be ob n5 vious that many'changes may be made therein without departing from its principles as defined in the appended claims.

I claim:

1. A furnace having a hearth, a heating chamber disposed above said hearth, means for moving the hearth relative to the chanr her, and inlet and outlet ports for heating gases located at different levels on one side of saidchamber to cause the gases to pass across the hearth at one level, turn, and then pass back across the hearth at another level before leaving the chamber.

2. A furnace having a hearth, a heating chamber disposed above said hearth, means for moving the hearth relative to the cham- The downward deflection of the her, .one or more inlet ports located at one sideof said chamber, adapted to cause heating gases to pass across the hearth, and one for moving the hearth relative to the chamber, said chamber including a roof adapted to reflect heat downwardly, On to the'hearth by radiation, one or more inlet ports for heating gases located at one side of the chamber adapted to cause the gases to pass across the roof andsupply heat to the hearth by.

radiation, one or' more outlet ports located in the same side of said chamber beneath said inlet ports, whereby said gases after passing across the chamber adjacent the roof as above mentioned, will turn downwardly and pass back across and in contact with the hearth to said outlet ports.

, 4. A furnace having a hearth, a heating chamber disposed above-said hearth, means for moving the hearth relative to the chamber, a recuperator disposed below the level of said chamber having passageways leading upwardly for gases to be heated and other passageways leading downwardly for the spent gases, together with one or more inlet ports communicating with said first mentioned passageways and disposed at one side of said chamber to project hot gases laterally thereacross, and one or more outlet ports communicating with said second mentioned recuperator passageways, said outlet ports being disposed on the same side of and beneath said inlet ports, whereby incoming gases rise through the recuperator, pass horizontally across the upper portion of said chamber, turn, and pass back across the chamber at a lower level and through said outlet ports to the spent gas passageways of the recuperator.

5. The method of operating a furnace hav? ing a hearth and a heating chamber disposed above the hearthwhich comprises passing a sheet of hot gases substantially horizontally across saidchambenpassing the gases back I across the hearth at a different level in the 6. A furnace having a heating chamber,

inlet ports for heating gases located at opposite sides of said chamber at an upper level, and outlet ports located respectively at a lower level than the inlet ports, whereby opposed sheets of hot gases are formed in said chamber at an upper level, means lo cated at the meeting point of said sheets to deflect them downwardly, whereby each respective sheet turns back on itself and passes back across the hearth at a lower level to its respective outlet ports.

7. A furnace having a heating chamber, inlet ports for heating gases located at opposite sides of said chamber at an upper level, and-outlet ports located respectively beneath said inlet ports whereby opposed streams of hot gases are formed in said chamber at an upper level, which streams turn downwardly and back-to pass out of their respective outlet ports at a lower level, the roof of said heating chamber being depressed in the central portion of the cham- 8. A furnace having a heating chamber,-

taneously causing hotgases to flow twice' over the moving material at different levels.

10. A furnace having a hearth, a heating chamber disposed above said hearth and including a roof adapted to reflect beat down- Wardly on to the hearth by radiation one or more inlet ports for heating gases located at oneside of the chamber adapted to cause the gases to pass across the roof and supply heat to the hearth by radiation, one or more outlet ports located in the same side of said chamber beneath said inlet ports, whereby said gases after passing across the chambeiz.

adjacent the roofas above mentioned, will turn downwardly and passback across and in contact with the hearth to said outlet ports, the under surface of said roof being substantially plane at least in the direction transverse to the flow of the hot gases thereacross.

In testimony that I claim the foregoing, I have hereunto set my hand this 4th day of January, 1926.

ALBERT L. CULBERTSON. 

